1. Field of the Invention
The present invention relates to structures of straddle-type all-terrain vehicles, and more specifically relates to a braking device for a straddle-type all-terrain vehicle.
2. Description of the Related Art
According to straddle-type all-terrain vehicles disclosed in Japanese Patent Applications Laid-open Sho 59 No.220472 and Hei 5 No.105150, braking devices are provided on axle shafts which are pivotally supported at the ends of the left and right swing arms. In order to protect the braking devices from obstacles and loose stones while the vehicles are in driving state, structures in which a plate-like guard member disposed under the swing arms have been proposed.
However, according to the above-proposed measures, since a separate guard must be formed, the number of parts increases. Therefore, there is a drawback in that the manufacturing cost, the number of fabrication steps, and the vehicle weight also increase.
In order to solve the above-described problems, an object of the present invention is to provide a braking device for a straddle-type all-terrain vehicle which can be protected by a simple structure without using the separate guard.
A braking device according to the present invention is used in a straddle-type all-terrain vehicle including rear swing arms which are attached to a vehicle body frame such that the rear swing arms can swing vertically, an axle shaft attached to the ends of the rear swing arms and extending in the lateral direction of the vehicle body, and a pair of wheels disposed one at each end of the axle shafts. The braking device is disposed above the axle shaft and is constructed as a mechanical braking device including a braking member which applies a braking force to the wheels; a swingable brake arm which activates the braking member; and a brake operating cable which is connected to a brake pedal or a brake lever at one end and to the brake arm at the other end, wherein the brake arm is provided with a projecting portion which is formed integrally with the brake arm at a position below a connecting portion with the brake operating cable, the projecting portion protecting the lower side of the connecting portion.
More specifically, according to the present invention, the braking device is disposed above the axle shaft in the straddle-type all-terrain vehicle having wheels disposed at the ends of the axle shaft, which is attached to the ends of the rear swing arms. Therefore, the braking device can be protected from an obstacle projecting on the road during driving.
In addition, the mechanical braking device includes the brake arm which activates the braking member by using the brake operating cable when the brake pedal or the brake lever is operated, and the brake arm is provided with the projecting portion which is formed integrally with the brake arm at a position below the connecting portion with the brake operating cable. Accordingly, a separately formed under-guard is not necessary. The projecting portion can be formed by using a simple die at a low cost, and fabrication processes can be more easily performed compared to when a separately formed component is used.
Preferably, a fulcrum around which the brake arm swings is disposed behind the axle shaft at the right or the left side of the main body of the braking device, and the brake arm extends vertically and is constructed such that the brake arm activates the braking member by swinging in the direction opposite to the direction in which the projecting portion extends. In such a case, even when the brake arm might happen to come into contact with an obstacle, such as a rock, a stub, etc., on the road during driving, the impact applied to the brake arm due to the contact can be reduced by the rotation of the brake arm. Accordingly, damage to the brake arm and the braking device can be minimized.
In addition, the projecting portion preferably extends toward the rear, and at least a part of the rear end area of the projecting portion is preferably formed so as to incline upward toward the rear. In such a case, even when the brake arm might happen to come into contact with an obstacle on the road during driving, damage to the brake arm and the braking device can be minimized.
In addition, according to the present invention, the connecting portion between the arm and the brake operating cable is preferably provided with a buffer portion which allows forward movement of the brake arm alone. In such a case, even when the brake arm is operated unexpectedly, the operation is not transmitted to the brake operating cable. Therefore, it becomes possible to improve durability of the brake operating cable. Furthermore, since the rotational movement is not transmitted to the brake pedal or the brake lever as well, which is connected to the brake operating cable at one end thereof. Accordingly, the operational stability can also be improved.
Accordingly, the braking device of the straddle-type all-terrain vehicle according to the present invention provides an excellent effect in that the braking device can be protected with a simple structure without using a guard.